Among the conventionally-known cultivating (tilling) machines and other similar working machines are ones which include a gas engine mounted on the machine body, a handle post extending rearwardly and upwardly from the machine body and a storage case provided along the handle post, and in which an entire cassette gas cylinder is accommodated in the storage case with a case lid opened and the engine is driven by fuel gas supplied from the cassette gas cylinder. One example of such working machines is a gas-engine-mounted working machine disclosed in JP 10-131809 A.
In the gas-engine-mounted working machine disclosed in JP 10-131809 A, a mouthpiece support section is provided for supporting a mouthpiece portion of the cassette gas cylinder in place within the storage case, and the mouthpiece portion of the cassette gas cylinder stored in the storage case is mounted to the mouthpiece support section. With the mouthpiece portion of the cassette gas cylinder mounted to the mouthpiece support section, a nozzle of the mouthpiece portion is pressed against the mouthpiece support section, and fuel gas contained in the cassette gas cylinder is supplied from the cassette gas cylinder to the gas engine via the nozzle. In mounting the mouthpiece portion of the cassette gas cylinder to the mouthpiece support section, it is necessary to positionally adjust the nozzle of the mouthpiece portion with respect to a fuel gas flow passage of the mouthpiece support section, i.e. align the nozzle with the fuel gas flow passage.
Further, a nozzle receiving portion (recessed portion) for receiving the nozzle is formed in the mouthpiece support section, and the fuel gas flow passage opens out to the nozzle receiving portion. Therefore, it is difficult to align the nozzle of the mouthpiece portion with the fuel gas flow passage, and thus, mounting the mouthpiece portion to the mouthpiece support section tends to require much time and effort.